1. Field of the Invention
The present invention relates to an ink jet recording apparatus capable of obtaining high quality images on a printing medium, and also, relates to a waste liquid collection member used therefore. More particularly, the invention relates to an ink jet recording apparatus that enables black ink and color ink or pigment ink and dyestuff ink to react and solidly fixes and makes them overly viscous on a printing medium, as well as to a waste liquid collection member used therefore.
The present invention is applicable to all the equipment that uses a printing medium, such as paper, cloth, unwoven cloth, OHP sheet, and as a specific equipment to which the invention is applicable is a printer, a copying machine, facsimile equipment, or other office equipment, or a large-scale production equipment, among some others.
2. Related Background Art
The ink jet recording method is utilized for a printer, a copying machine, facsimile equipment, and others, because with this method, it is easier to make the apparatus smaller with a lesser amount of noises at a lower running cost, as well as the ease with which color printing is made possible.
However, the problems characteristic of the ink jet printing method may be encountered in some cases as given below.
1) Printing is executed by discharging ink droplets from an ink jet head to a recording medium, such as paper, OHP film. As a result, fine ink droplets (mist) generated aside from the main ink droplets discharged, and splash of ink droplets discharged to a printing medium may cause ink adhesion to the ink discharge port surface of the ink jet head, and these are brought to get together around ink discharge ports. Also, if foreign substance, such as paper particles, adheres to them, ink discharge is impeded to ensue in the twisted discharge in the unexpected direction or some hindrance may take place, such as to disable ink discharges.
2) At non-printing time, to be exact, with no discharge being made for a long time, ink in an ink jet head is evaporated and dried to clog the nozzle with the ink that has become overly viscous and solidified. This condition causes discharge defects, such as twisted discharge, disabled discharge.
The ink jet recording apparatus is generally provided with the following recovery means in order to solve the aforesaid problems 1) and 2).
At non-printing time, the ink jet head is capped to prevent ink in the nozzle from being evaporated and dried so as not to allow it to become overly viscous or solidified. Also, if ink should become overly viscous and solidified to cause discharge defects or any foreign substance that has not been removed by a blade adheres to the discharge port surface, such overly viscous ink in the nozzle is exhausted by use of a suction pump connected with the cap, thus performing the recovery process for obtaining normal discharges.
The exhausted ink is absorbed by a waste ink absorbent provided for the ink jet recording apparatus through the tube or the like that is arranged on the downstream side of the suction pump. Here, the capacity of the waste ink absorbent is determined the numbers of defective prints, the frequency of recovery operations, the amount of ink pushed out or sucked per recovery operation, and the amount of ink mist discharged. However, from the viewpoint of the entire structure of the apparatus, it is better to make the capacity of the waste ink absorbent smaller for more compact arrangement. Then, there is no restriction on the location of its installation to make it possible to anticipate the lower cost installation thereof.
Nevertheless, if the capacity of the waste ink absorbent is made smaller than the required amount, the waste ink absorbent should be replaced more frequently to make its maintenance more complicated, among some others. Also, if the capacity is made to deal with the required amount, the size of the waste ink absorbent should become larger to invite not only increased costs, but to make the ink jet recording apparatus main body larger eventually.
To cope with such situation, there is disclosed an art to minimize the volume of a waste ink absorbent by the utilization of ink evaporation in the specification of Japanese Patent Laid-Open Application 57-22065.
Meanwhile, when a color image is obtained on the printing medium that is the so-called ordinary paper sheet by use of the apparatus utilizing the ink jet printing method, it is difficult to from the image that does not show any ooze between black and other colors, thus degrading color image quality considerably.
As a result, there is used an art to suppress ooze between black and other colors in such a manner that the black ink and color ink discharged by an ink jet head are allowed to act on a printing medium to solidify and make them overly viscous, thus suppressing ooze between black and such color thus discharged. To solve the problems characteristics of the ink jet recording apparatus while using this art, it is required to provide recovery means both for the black ink jet nozzle and the color ink jet nozzle in consideration of the behavior of the ink system in which black ink and color ink should react to be solidified and become overly viscous.
Also, in recent years, there has been a tendency to use the black ink that contains pigment component in order to elevate the quality of black characters of a text document or the like.
Under such circumstances, when a suction recovery process is performed for the aforesaid ink jet recording apparatus, there exist eventually two kinds of ink materials, black and other colors, in the waste liquid absorbed by the waste liquid absorbent.
However, these two kinds of waste liquids have the properties to become overly viscous when mixed, and the mixture of waste liquids is accumulated in the absorbent to make it difficult for them to be absorbed eventually.
Also, in order to avoid the accumulation of waste liquids, it may be possible to provide an absorbent for each of those used for black and colors, respectively. However, this arrangement results in considerably higher costs, and the ink jet recording apparatus main body should also be made larger.
Further, although the absorption of dyestuff color ink to the absorbent is stable substantially with respect to its use conditions or the like, the status of waste liquid of pigment black ink changes drastically depending on its use conditions.
In other words, at the time of continuous use under high humidity, there is a need for keeping the absorbent in condition so as not to allow waste liquid to over flow even when the ink jet recording apparatus is tilted, because waste liquid remains to be in the state of fluid. On the contrary, at the time of intermittent use under low humidity, or the like, there is almost no absorption to the absorbent, and the pigment component is solidified and accumulated. As a result, a problem is encountered that the exhaust port of waste liquid is clogged.
It is an object of the present invention to provide a highly reliable ink jet recording apparatus to form images by discharging reactive ink to a printing medium, which is capable of performing waste liquid process efficiently so as not to allow waste liquid to be accumulated to clog the exhaust port of waste liquid, and also, to provide a waste liquid collection member used for such apparatus.
It is another object of the invention to provide an ink jet recording apparatus comprising first recovery means for recovering the black ink discharge portion for discharging black ink; second recovery means for recovering the color ink discharge portion for discharging color ink; a waste liquid collection member provided with a waste liquid absorbent for absorbing waste liquid exhausted from the first recovery means and the second recovery means, and a waste liquid correction frame for housing the waste liquid absorbent; a first waste liquid carrying path for carrying waste liquid exhausted from the first recovery means to the waste liquid collection member; and a second waste liquid carrying path for carrying waste liquid exhausted from the second recovery means to the waste liquid collection member. For this ink jet recording apparatus, waste liquid exhausted from the first waste liquid carrying path is exhausted to the inner bottom face of the waste liquid collection frame, and waste liquid exhausted from the second waste liquid carrying path is exhausted to the waste liquid absorbent.
It is still another object of the invention to provide an ink jet recording apparatus comprising first recovery means for recovering the pigment ink discharge portion for discharging pigment ink; second recovery means for recovering the dyestuff ink discharge portion for discharging dyestuff ink reacting to pigment ink; a waste liquid collection member provided with a waste liquid absorbent for absorbing waste liquid exhausted from the first recovery means and the second recovery means, and a waste liquid correction frame for housing the waste liquid absorbent; a first waste liquid carrying path for carrying waste liquid exhausted from the first recovery means to the waste liquid collection member; and a second waste liquid carrying path for carrying waste liquid exhausted from the second recovery means to the waste liquid collection member. For this ink jet recording apparatus, waste liquid exhausted from the first waste liquid carrying path is exhausted to the inner bottom face of the waste liquid collection frame, and waste liquid exhausted from the second waste liquid carrying path is exhausted to the waste liquid absorbent.
It is a further object of the invention to provide a waste liquid collection member for use of an ink jet recording apparatus having a waste liquid absorbent for absorbing waste liquid and a waste liquid collection frame housing the waste liquid absorbent. For this waste liquid collection member, waste liquid exhausted from the black ink discharge portion for discharging black ink is exhausted to the inner bottom face of the waste liquid collection frame, and waste liquid exhausted from the color ink discharge portion for discharging color ink reacting to black ink is exhausted to the waste liquid absorbent.
It is still a further object of the invention to provide a waste liquid collection member for use of an ink jet recording apparatus having a waste liquid absorbent for absorbing waste liquid, and a waste liquid collection frame housing the waste liquid absorbent. For this waste liquid collection member, waste liquid exhausted from the pigment ink discharge portion for discharging pigment ink is exhausted to the inner bottom face of the waste liquid collection frame, and waste liquid exhausted from the dyestuff ink discharge portion for discharging dyestuff ink reacting to pigment ink is exhausted to the waste liquid absorbent.
In accordance with the present invention, the ink jet recording apparatus that forms images by discharging reactive ink to a printing medium makes it possible to collect waste liquid efficiently without any direct reaction between waste liquids themselves that may impede absorption to the absorbent or any possible clogging of the exhaust port by the accumulation thereof, because black ink or pigment ink is exhausted to the inner bottom face of the waste liquid collection frame, and color ink or dyestuff ink is exhausted to the waste liquid absorbent for dispersion when overly viscous ink in each nozzle is exhausted by means of the suction pump connected with the cap for the execution of recovery process to recovery discharges to the normal condition.
Also, the state of pigment black ink is kept in the waste liquid absorbent even when it is in the form of liquid, and there is no possibility that waste liquid leaks outside the apparatus. Further, even when pigment black ink is condition to be overly viscous due to drying, waste liquid can be dispersed flatly on the inner bottom face of the waste liquid collection member. In a case where it is accumulated, the distance from the exhaust port thereto can be made long to enable the accumulated ink on the opening and grooved portions to flow so as not to clog them.